脂多糖对不同脑成熟程度早期新生鼠髓鞘发育的影响及肿瘤坏死因子-α表达变化  

Effects of lipopolysaccharide on myelination of early neonatal rat at different maturity levels and the changes of tumor necrosis faetor-α expression

作　　者：安晶慧[1] 毛健[1] 周卓[1] 高红[1] 

机构地区：[1]中国医科大学附属盛京医院新生儿科,沈阳110004

出　　处：《中国小儿急救医学》2013年第3期257-260,264,共5页Chinese Pediatric Emergency Medicine

摘　　要：目的通过向2日龄（P2）、7日龄（P7）Wistar新生鼠腹腔注射相同剂量的脂多糖（lipopolysaccharide，LPS），采用2’，3’环核苷酸3’磷酸二酯酶（2’，3’cyclic nucleotide phosphodiesterase，CNPase）和髓鞘碱性蛋白（myelinbasicprotein，MBP）分别标记未成熟少突胶质细胞和成熟少突胶质细胞，动态监测感染因素对两组新生鼠脑白质区髓鞘发育的影响，并检测这一过程中脑组织肿瘤坏死因子（tumornecrosisfactor，TNF）-α表达的变化，探讨TNF-α在脑白质损伤（white matter damhge，WMD）发生中的作用。方法将96只新生Wistar大鼠随机分为4组，每组24只，A组（P2新生鼠腹腔注射LPS5．0mg／kg），B组（P7新生鼠腹腔注射LPS5．0mg／kg），C1、C2组（分别向P2或P7新生鼠腹腔注射等量生理盐水）。观察各组新生鼠脑组织病理变化，免疫组织化学技术测定给药后24h脑组织CNPase蛋白表达变化及日龄14d（P14）脑组织MBP蛋白表达的变化，RT—PCR法测定给药后4h脑组织中TNF-αmRNA表达的变化。结果A组大鼠脑组织病理可见胼胝体区、外囊区灶性出血及侧脑室内出血，P14时胼胝体区可见软化灶，软化灶的周围可见胶质增生。而B组和C1、C2组脑白质区组织结构清晰，无明显的细胞增生和出血。A组脑室周围白质区阳性CNPase表达程度及面积较C1组弱（106．93±2．62vs113．67±2．69，P〈0．01），B组染色程度及面积亦较C2组弱（96．37±1．82vs101．65±2．01，P〈0．01）。P14时，与C2组相比，在胼胝体及放射冠区A组MBP染色明显减少（128．21±2．99vs134．81±2．98，P〈0．01），而B组较C2组无明显改变（134．77±3．68vs134．81±2．98，P〉0，05）。给药后4h，A组新生鼠脑组织中TNF—dmRNA表达相对值较B组增强（1．79±0．04vs1．18±0．04，P〈0．01）。结论处于脑发育中的未成熟新生鼠腹腔注射LPS可对脑的髓鞘发育产生重要影响，导Objective To monitor the function of infection on myelination in white matter damage, neonatal Wistar rats of postnatal day 2 （ P2 ） and postnatal day 7 （ P7 ） were injected intraperitoneally with the same doses of lipopolysaccharides （ LPS ）, and 2＇, 3 ＇-cyclic nucleotide phosphodiesterase （CNPase） and myelin basic protein （MBP） were labeled in immature oligodendrocytes and mature oligodendrocytes. To investigate the function of tumor necrosis factor（TNF）-α according to test the change of TNF-α expression in the brain. Methods Ninty-six neonatal Wistar rats were randomly divided into four groups （each group 24 rats） ： group A： LPS （ 5.0 mg/kg ） was injected intraperitoneally on P2; group B ： LPS （5. 0 mg/kg） was injected intraperitoneally on P7 ;group C1 and C2 were control groups in which equal amount of normal saline was injected intraperitoneally on P2 or P7. The expression of CNPase at 24 h after injection and MBP at P14 in brain tissue of each group were measured by immunohistochemistry and express of TNF-α mRNA at 4 h after the injection was measured by RT-PCR. Results Punctate hemorrhage in the corpus callosum,external capsule and intraventricular hemorrhage were seen in group A. Periventricular leukomalacia appeared in the corpus callosum and glial cells hyperplasia could be seen perivenWicular in P14 rat brains, but not found in the group B and any of the saline-injected rat brains. Compared with group C1 and C2 respectively, CNPase-positive cells showed obvious decrease in the area of white matter in periventricular in group A（ 106. 93 ± 2. 62 vs 113.67 ± 2. 69, P 〈 0. 01 ） and group B （ 96. 37 ± 1.82 vs 101.65 ± 2. 01, P 〈 0.01 ）. Following LPS treatment in group A,the protein expression of MBP in neonatal brain decreased evidently compared with group C1 at P14 （ 128.21 ± 2. 99 vs 134. 81 ± 2. 98, P 〈 0. 01 ）, while no significant change was found between group B and group C2（ 134. 77 ±3. 68 vs 134. 81 ±2. 98 ,P 〉0. 05）.

关 键 词：脂多糖 髓鞘 脑白质损伤 肿瘤坏死因子-Α 大鼠 新生 

分 类 号：R722.6[医药卫生—儿科]